WORK IN PROGRESS.

chrome/browser/extensions/syncable_extension_settings_storage.cc

Index: chrome/browser/extensions/syncable_extension_settings_storage.cc
diff --git a/chrome/browser/extensions/syncable_extension_settings_storage.cc b/chrome/browser/extensions/syncable_extension_settings_storage.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3c862d2552ebdd47eac6ec884370f139fd883b35
--- /dev/null
+++ b/chrome/browser/extensions/syncable_extension_settings_storage.cc
@@ -0,0 +1,389 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/syncable_extension_settings_storage.h"
+
+#include "base/bind.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "base/task.h"
+#include "chrome/browser/extensions/extension_settings_sync_helper.h"
+#include "chrome/browser/sync/api/sync_data.h"
+#include "chrome/browser/sync/protocol/extension_setting_specifics.pb.h"
+
+SyncableExtensionSettingsStorage::SyncDeps::SyncDeps(
+    SyncChangeProcessor* processor) : processor_(processor) {
+  DCHECK(processor != NULL);
+}
+
+SyncableExtensionSettingsStorage::SyncDeps::~SyncDeps() {
+}
+
+SyncableExtensionSettingsStorage::SyncableExtensionSettingsStorage(
+    std::string extension_id, ExtensionSettingsStorage* delegate)
+    : extension_id_(extension_id), delegate_(delegate), sync_deps_(NULL) {}
+
+SyncableExtensionSettingsStorage::~SyncableExtensionSettingsStorage() {}
+
+void SyncableExtensionSettingsStorage::Get(
+    const std::string& key, ExtensionSettingsStorage::Callback* callback) {
+  delegate_->Get(key, callback);
+}
+
+void SyncableExtensionSettingsStorage::Get(
+    const ListValue& keys, ExtensionSettingsStorage::Callback* callback) {
+  delegate_->Get(keys, callback);
+}
+
+void SyncableExtensionSettingsStorage::Get(
+    ExtensionSettingsStorage::Callback* callback) {
+  delegate_->Get(callback);
+}
+
+namespace {
+
+class AddOrUpdateSyncCallback : public ExtensionSettingsStorage::Callback {
+ public:
+  AddOrUpdateSyncCallback(
+      Callback* delegate,
+      const std::string& extension_id,
+      base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps)
+      : delegate_(delegate),
+        extension_id_(extension_id),
+        sync_deps_(sync_deps) {}
+
+  void OnSuccess(DictionaryValue* settings) OVERRIDE {
+    if (!sync_deps_) {
+      delegate_->OnSuccess(settings);
+      return;
+    }
+
+    SyncChangeList sync_changes;
+    for (DictionaryValue::key_iterator it = settings->begin_keys();
+        it != settings->end_keys(); ++it) {
+      Value* value;
+      settings->GetWithoutPathExpansion(*it, &value);
+      if (sync_deps_->keys()->count(*it)) {
+        // TODO Key is synced, send ACTION_UPDATE to sync.
+        LOG(INFO) << "Pushing sync update to sync for " << *it;
+        sync_changes.push_back(ExtensionSettingsSyncHelper::CreateUpdate(
+            extension_id_, *it, *value));
+      } else {
+        // TODO Key is not synced, send ACTION_ADD to sync.
+        LOG(INFO) << "Pushing sync add to sync for " << *it;
+        sync_changes.push_back(ExtensionSettingsSyncHelper::CreateAdd(
+            extension_id_, *it, *value));
+      }
+    }
+
+    SyncError error =
+        sync_deps_->processor()->ProcessSyncChanges(FROM_HERE, sync_changes);
+    if (error.IsSet()) {
+      LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    } else {
+      // Sync was successful, record those keys as synced.
+      sync_deps_->keys()->insert(settings->begin_keys(), settings->end_keys());
+    }
+
+    delegate_->OnSuccess(settings);
+  }
+
+  void OnFailure(const std::string& error) {
+    LOG(WARNING) << "Settings operation failed, not sending to sync: " << error;
+    delegate_->OnFailure(error);
+  }
+
+ private:
+  scoped_ptr<Callback> delegate_;
+  std::string extension_id_;
+  base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps_;
+};
+
+}  // namespace
+
+void SyncableExtensionSettingsStorage::Set(
+    const std::string& key,
+    const Value& value,
+    ExtensionSettingsStorage::Callback* callback) {
+  if (sync_deps_ != NULL) {
+    callback = new AddOrUpdateSyncCallback(
+        callback, extension_id_, sync_deps_->AsWeakPtr());
+  }
+  delegate_->Set(key, value, callback);
+}
+
+void SyncableExtensionSettingsStorage::Set(
+    const DictionaryValue& values,
+    ExtensionSettingsStorage::Callback* callback) {
+  if (sync_deps_ != NULL) {
+    callback = new AddOrUpdateSyncCallback(
+        callback, extension_id_, sync_deps_->AsWeakPtr());
+  }
+  delegate_->Set(values, callback);
+}
+
+namespace {
+
+class RemoveFromSyncCallback : public ExtensionSettingsStorage::Callback {
+ public:
+  RemoveFromSyncCallback(
+      Callback* delegate,
+      const std::string& extension_id,
+      // Ownership of keys_to_remove is taken.
+      std::set<std::string>* keys_to_remove,
+      base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps)
+      : delegate_(delegate),
+        extension_id_(extension_id),
+        keys_to_remove_(keys_to_remove),
+        sync_deps_(sync_deps) {
+    DCHECK(!keys_to_remove->empty());
+  }
+
+  void OnSuccess(DictionaryValue* settings) OVERRIDE {
+    if (!sync_deps_) {
+      delegate_->OnSuccess(settings);
+      return;
+    }
+
+    SyncChangeList sync_changes;
+    for (std::set<std::string>::iterator it = keys_to_remove_->begin();
+        it != keys_to_remove_->end(); ++it) {
+      LOG(INFO) <<
+          "Pushing sync remove to sync for " << extension_id_ << "/" << *it;
+      SyncChange sync_delete =
+          ExtensionSettingsSyncHelper::CreateDelete(extension_id_, *it);
+      sync_changes.push_back(sync_delete);
+    }
+
+    SyncError error =
+        sync_deps_->processor()->ProcessSyncChanges(FROM_HERE, sync_changes);
+    if (error.IsSet()) {
+      LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    } else {
+      // Sync was successful, record those keys as deleted from sync.
+      sync_deps_->keys()->erase(
+          keys_to_remove_->begin(), keys_to_remove_->end());
+    }
+
+    delegate_->OnSuccess(settings);
+  }
+
+  void OnFailure(const std::string& error) {
+    LOG(WARNING) << "Settings operation failed, not sending to sync: " << error;
+    delegate_->OnFailure(error);
+  }
+
+ private:
+  scoped_ptr<Callback> delegate_;
+  std::string extension_id_;
+  scoped_ptr<std::set<std::string> > keys_to_remove_;
+  base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps_;
+};
+
+}  // namespace
+
+void SyncableExtensionSettingsStorage::Remove(
+    const std::string& key, ExtensionSettingsStorage::Callback* callback) {
+  if (sync_deps_ != NULL) {
+    std::set<std::string>* keys_to_remove = new std::set<std::string>();
+    keys_to_remove->insert(key);
+    callback = new RemoveFromSyncCallback(
+        callback,
+        extension_id_,
+        keys_to_remove,
+        sync_deps_->AsWeakPtr());
+  }
+  delegate_->Remove(key, callback);
+}
+
+void SyncableExtensionSettingsStorage::Remove(
+    const ListValue& keys, ExtensionSettingsStorage::Callback* callback) {
+  if (sync_deps_ != NULL) {
+    std::set<std::string>* keys_to_remove = new std::set<std::string>();
+    for (ListValue::const_iterator it = keys.begin(); it != keys.end(); ++it) {
+      std::string key_to_remove;
+      if ((*it)->GetAsString(&key_to_remove)) {
+        keys_to_remove->insert(key_to_remove);
+      }
+    }
+    callback = new RemoveFromSyncCallback(
+        callback,
+        extension_id_,
+        keys_to_remove,
+        sync_deps_->AsWeakPtr());
+  }
+  delegate_->Remove(keys, callback);
+}
+
+void SyncableExtensionSettingsStorage::Clear(
+    ExtensionSettingsStorage::Callback* callback) {
+  if (sync_deps_ != NULL) {
+    callback = new RemoveFromSyncCallback(
+        callback,
+        extension_id_,
+        // Remove all the synced keys.
+        new std::set<std::string>(*sync_deps_->keys()),
+        sync_deps_->AsWeakPtr());
+  }
+  delegate_->Clear(callback);
+}
+
+void SyncableExtensionSettingsStorage::DeleteSoon() {
+  delegate_->DeleteSoon();
+  delete this;
+}
+
+// Sync-related methods.
+
+namespace {
+
+class SendAllLocalSettingsToSync : public ExtensionSettingsStorage::Callback {
+ public:
+  SendAllLocalSettingsToSync(
+      const std::string& extension_id,
+      base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps)
+      : extension_id_(extension_id), sync_deps_(sync_deps) {}
+
+  virtual void OnSuccess(DictionaryValue* settings) OVERRIDE {
+    scoped_ptr<DictionaryValue> settings_ownership(settings);
+    if (!sync_deps_) {
+      return;
+    }
+
+    SyncChangeList add_to_sync;
+    for (DictionaryValue::key_iterator it = settings->begin_keys();
+        it != settings->end_keys(); ++it) {
+      Value* value;
+      settings->GetWithoutPathExpansion(*it, &value);
+      add_to_sync.push_back(ExtensionSettingsSyncHelper::CreateAdd(
+          extension_id_, *it, *value));
+    }
+
+    SyncError error =
+        sync_deps_->processor()->ProcessSyncChanges(FROM_HERE, add_to_sync);
+    if (error.IsSet()) {
+      LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    } else {
+      // Sync was successful, record those keys as synced.
+      sync_deps_->keys()->insert(settings->begin_keys(), settings->end_keys());
+    }
+  }
+
+  virtual void OnFailure(const std::string& error) OVERRIDE {
+    LOG(WARNING) << "Settings operation failed, not sending to sync: " << error;
+  }
+
+ private:
+  std::string extension_id_;
+  base::WeakPtr<SyncableExtensionSettingsStorage::SyncDeps> sync_deps_;
+};
+
+class OverwriteLocalSettingsCallback
+  : public ExtensionSettingsStorage::Callback {
+ public:
+  OverwriteLocalSettingsCallback(
+      // Ownership NOT taken.
+      SyncableExtensionSettingsStorage* storage,
+      // Ownership taken.
+      DictionaryValue* sync_state)
+      : storage_(storage), sync_state_(sync_state) {}
+
+  virtual void OnSuccess(DictionaryValue* local_state) {
+    scoped_ptr<DictionaryValue> local_state_ownership(local_state);
+    // Pretend they're sync changes to process.
+    ExtensionSettingsSyncDataList sync_changes;
+    for (DictionaryValue::key_iterator it = local_state->begin_keys();
+        it != local_state->end_keys(); ++it) {
+      Value* sync_value;
+      if (sync_state_->RemoveWithoutPathExpansion(*it, &sync_value)) {
+        Value* local_value;
+        local_state->GetWithoutPathExpansion(*it, &local_value);
+        if (!local_value->Equals(sync_value)) {
+          // Sync value is different, update locally with new value.
+          sync_changes.push_back(ExtensionSettingsSyncData(
+              SyncChange::ACTION_UPDATE, "", *it, sync_value));
+        }
+      } else {
+        // No sync value, delete locally.
+        sync_changes.push_back(ExtensionSettingsSyncData(
+            SyncChange::ACTION_DELETE, "", *it, new DictionaryValue()));
+      }
+    }
+
+    for (DictionaryValue::key_iterator it = sync_state_->begin_keys();
+        it != sync_state_->end_keys(); ++it) {
+      Value* sync_value;
+      // Missing local value for synced setting, add locally.
+      // If it's safe to RemoveWithoutPathExpansion the DeepCopy would be
+      // unnecessary.
+      sync_state_->GetWithoutPathExpansion(*it, &sync_value);
+      sync_changes.push_back(ExtensionSettingsSyncData(
+          SyncChange::ACTION_ADD, "", *it, sync_value->DeepCopy()));
+    }
+
+    if (!sync_changes.empty()) {
+      storage_->ProcessSyncChanges(sync_changes);
+    }
+  }
+
+  virtual void OnFailure(const std::string& error) {
+    LOG(WARNING) <<
+        "Settings operation failed, local state not in sync: " << error;
+  }
+
+ private:
+  // XXX(kalman): weak pointer or refcount or ughhhhh.
+  SyncableExtensionSettingsStorage* storage_;
+  scoped_ptr<DictionaryValue> sync_state_;
+};
+
+}  // namespace
+
+void SyncableExtensionSettingsStorage::StartSyncing(
+    const DictionaryValue& sync_state, SyncChangeProcessor* sync_processor) {
+  DCHECK(sync_deps_ == NULL);
+  sync_deps_ = new SyncDeps(sync_processor);
+  sync_deps_->keys()->insert(sync_state.begin_keys(), sync_state.end_keys());
+
+  // Push local state to sync if there is no sync data yet, otherwise overwrite
+  // local state with sync state (via a callback).
+  if (sync_state.empty()) {
+    Get(new SendAllLocalSettingsToSync(extension_id_, sync_deps_->AsWeakPtr()));
+  } else {
+    Get(new OverwriteLocalSettingsCallback(this, sync_state.DeepCopy()));
+  }
+}
+
+void SyncableExtensionSettingsStorage::StopSyncing() {
+  DCHECK(sync_deps_ != NULL);
+  delete sync_deps_;
+  sync_deps_ = NULL;
+}
+
+void SyncableExtensionSettingsStorage::ProcessSyncChanges(
+    const ExtensionSettingsSyncDataList& sync_changes) {
+  DCHECK(sync_deps_ != NULL);
+  DCHECK(!sync_changes.empty()) << "No sync changes for " << extension_id_;
+  for (ExtensionSettingsSyncDataList::const_iterator it = sync_changes.begin();
+      it != sync_changes.end(); ++it) {
+    switch (it->change_type()) {
+      case SyncChange::ACTION_ADD:
+      case SyncChange::ACTION_UPDATE:
+        sync_deps_->keys()->insert(it->key());
+        delegate_->Set(
+            it->key(),
+            *it->value(),
+            new ExtensionSettingsStorage::NoopCallback());
+        break;
+      case SyncChange::ACTION_DELETE:
+        sync_deps_->keys()->erase(it->key());
+        delegate_->Remove(
+            it->key(),
+            new ExtensionSettingsStorage::NoopCallback());
+        break;
+      default:
+        NOTREACHED();
+    }
+  }
+}